Silicon carbide devices comprise a breakdown field strength which is similarly high as the maximal tolerable field strength in thermally grown silicon dioxide SiO2 due to the large band gap, if a high long term reliability is required. At the semiconductor surface (e.g. at the edge termination), very high electrical fields occur on silicon carbide devices (SiC-device) which stress at least the passivation layers.
Some possible concepts for edge terminations for silicon carbide are based on junction termination extension (JTE), variation of lateral doping (VLD), field plate and combinations thereof. However, silicon carbide is a very hard material. Therefore, mechanical damages can occur during the separation of the semiconductor, which may be done with a diamond comprising saw blade. In some cases, this may distort the backside metallization and consequently leads to difficulties during assembly or in the long term reliability. Particularly crystal defects can migrate into the active device area. Therefore, a security distance of some micrometers up to some ten micrometers between the saw trace and the edge termination should be kept, which is especially expensive for silicon carbide.